Problem: Simplify the following expression: $r = \dfrac{5q}{9} + \dfrac{10q}{9}$
Answer: Since the expressions have the same denominator we simply combine the numerators: $r = \dfrac{5q + 10q}{9}$ Combine like terms: $r = \dfrac{15q}{9}$ Simplify by dividing numerator and denominator by 3: $r = \dfrac{5q}{3}$